How to Fix Flooded Basement in Old Home

  • waterproofing basement walls
  • Transcript

    LESLIE: Keith in New York is on the line and has a flooded basement in old home. What is going on?

    KEITH: During times of really heavy rains and downpours, we’ve noticed that the rain comes in through the rocks of the cement wall that our house was built upon. And our house was built back in the 1800s, so it’s been a slow process. And now it just seems like it’s coming in all at once.

    TOM: Well, that sounds like a really solid house, Keith. I mean I personally have a house that was built in 1886 and I’ve got old brick foundation here. But I can definitely sympathize with a flooded basement in old home. And the good news is that this is a very easy problem to solve. One that is very, very common, as well.

    And the reason I know it’s going to be super simple for you to solve is because you mentioned that this problem is consistent with heavy rainfall. And that means one thing and one thing only and that is that you have some drainage improvements to make, my friend. But those improvements are not inside the house, they’re outside the house.

    So, you need to look very carefully at the foundation perimeter. And you start with the gutter system, right? You’ve got to make sure you have gutters. You’ve got to make sure the gutters are not clogged and that the downspouts are clear and free-flowing and discharging at least 4 to 6 feet away from the house. You’ve got to manage that roof water. If you let the water run off the roof, right along the foundation, it’s going to yield a flooded basement in old home. That is the number-one cause of the condition that you’re describing.

    The number-two cause is the angle of the soil at the foundation perimeter. Sometimes, if the soil – soil is going to settle over time, especially if you had a water problem. It settles as it goes. You can collect a lot of water because it’s not running away from the house. So, what you need to do is add some soil to the foundation perimeter to slope it away. And you want to use clean fill dirt, not topsoil, so that it can be tamped down and give you a good slope. You want to drop about 6 inches over 4 feet. You can add some mulch or you can add some pebbles or really, sod, anything you want on top of that. But you’ve got to have that grade established first.

    Once that grade is established and once those gutters are clean, free-flowing – and also, make sure you’ve got enough downspouts. Generally speaking, you want one downspout for about every 400 to 600 square feet of roof. So if you stand back from your house and kind of try to rough that out, maybe figure out kind of in your mind what a 10×10 section looks like and just kind of do the math, make sure you’ve got enough spouts.

    And managing that roof water, managing the drainage around the foundation perimeter, that will stop your flooded basement in old home in a heartbeat.

    KEITH: Cool. Because we built a little gutter system when it hits the ground now, because we tried to move it away from the basement area. When the rain comes down, it comes right off on a slant.

    TOM: Yep. Well, do you have a gutter system?

    KEITH: On the new part, yes. This is a really old roof.

    TOM: Well, if you don’t have gutters on the whole house, that’s the first place to start.

    And by the way, if you’re going to put it up, I would put up the 6-inch gutters, not the 4-inch gutters. I would step up the gutter size because I find that it’s not that much more money. And if you do that, you’ll find that they clog a lot less frequently because the downspouts are just wider.

    KEITH: Well, thank you very much.

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